Ego wanted to expand himself throughout the universe just because he was bored. And because of his superiority complex; he believed he was the only being in the universe that mattered, so he was insensitive towards all other life-forms. Thanos believed he was doing the right thing in reducing the universe's population, but his means were brutal.

they both are evil. They are both horrible fathers. But, Thanos' backstory actually made me cry and Ego's backstory made me scoff. Killing his baby mamas and his babies if they fail? ! Just so he can be powerful af? ! Thanos on the other hand just wants equality, He just doesn't want the same thing to happen as what happened on titan

Would comment but my clever friends on the right said it best- Ego is essentially the maniac Napoleon of space and time who seeks to conquer the universe in the name of just that- his ego. Ego does this for satisfaction. Meanwhile, Thanos believed this to be the true way to save humanity- to him it was a noble and just quest for peace.

What if there isn't enough food on earth for the 10 billion people soon to be born on earth; what if we need to adopt a Thanos ideology to survive? Who gets to live and who gets to die? Do we kill the lazy worthless people with neanderthal intellect? Or do we keep it truly equal?

@MarkUts Thanos is compelling. I sympathize with his desire to prevent overpopulation. I too agree that Earth will become overpopulated and lead to a resources shortage if the human population is left unchecked. But what can be done that will work the most? The only things I can think of is an Inferno scenario in which a percentage of the human population is reduced or sterilized. Sterilization sounds more humane than a plague, but are there more ethical measures?